• Title/Summary/Keyword: Binding state

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The Adsorptions and Configurations of CO Molecules on W (110) and W (100) Surface: Molecular Orbital Theory

  • Choe, Sang-Joon;Kang, Hae-Jin;Park, Dong-Ho;Huh, Do-Sung;Lee, Soon-Bo
    • Bulletin of the Korean Chemical Society
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    • v.25 no.9
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    • pp.1314-1320
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    • 2004
  • The adsorption and configuration of CO molecules adsorbed on W (110) and W (100) surfaces have been calculated by the atomic superposition and electron delocalization molecular orbital (ASED-MO) method. Referred to as the ASED-MO method, it has been used in the present study to calculate the geometries, binding energies, vibrational frequencies, orbital energies, reduced overlap population (ROP), and charges. From these results adsorption properties of ${\alpha}$-state and ${\beta}$-state were deduced. The calculated binding energies are in good agreement with the experimental result. On the W (110), the calculated average binding energies are 2.56 eV for the end-on configuration and 3.20 eV for the lying-down configuration. Calculated vibrational frequency is 1927 $cm^{-1}$ at a 1-fold site and 1161 $cm^{-1}$ at a long-bridge (2) site. These results are in reasonable agreement with experimental values. On the W(100) surface, calculated average binding energies of the end-on and the lying-down are 2.54 eV and 4.02 eV respectively. The differences for binding energy and configuration on the surfaces are explained on the basis of surface-atom coordination and atom-atom spacing. In the favored lyingdown CO configuration on the W(110) and W(100) surfaces, 4 ${\sigma}$ and 1 ${\pi}$ donation interactions, coupled with the familiar 5 ${\sigma}$ donation to the surfaces and back-donations to the CO 2 ${\pi}^{\ast}$ orbital, are responsible for adsorption to the surface.

Characterization of Fatty Acid Digestion of Beijing Fatty and Arbor Acres Chickens

  • Yuan, J.M.;Guo, Y.M.;Yang, Y.;Wang, Z.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.8
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    • pp.1222-1228
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    • 2007
  • The aim of this experiment was to compare the characterization of fatty acid digestion of Beijing Fatty (BF) and Arbor Acres (AA) chickens. One-day-old male AA and BF chickens were raised in the same house, and fed with the same diet. We first evaluated utilization of dietary fatty acids in chickens by the total collection procedure, and chickens were then killed to compare the abundance of intestinal mRNA expression of liver-fatty acid binding protein (L-FABP) and intestinal-fatty acid binding protein (I-FABP) by Real-time PCR, and also the pH of intestinal mucosa at 3 and 6 weeks of age. Another group of chickens were sampled at 6 weeks of age to compare the total bile acid concentration in serum, and lipase activity in contents of the small intestine. Results showed that compared to AA chickens, BF chickens had higher lipase activity in the content of the small intestine (p<0.05), greater total bile acid content in portal vein blood (p<0.05) at 6 weeks of age, lower intestinal mucosal pH at both 3 weeks (p<0.05) and 6 weeks (p<0.05) of age, and higher abundance of liver-fatty acid binding protein (L-FABP) mRNA expression in intestine tissues at 6 weeks of age (p<0.05), and higher digestibility of fatty acids at both 3 and 6 weeks (p<0.05) of age. There was no difference in I-FABP mRNA expression between AA and BF chickens at either age. Thus, BF chickens had greater fatty acids utilization than AA chickens that was associated with L-FABP, lipase activity, bile acid content and intestinal mucosal pH.

High glucose induces differentiation and adipogenesis in porcine muscle satellite cells via mTOR

  • Yue, Tao;Yin, Jingdong;Li, Fengna;Li, Defa;Du, Min
    • BMB Reports
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    • v.43 no.2
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    • pp.140-145
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    • 2010
  • The present study investigated whether the mammalian target of rapamycin (mTOR) signal pathway is involved in the regulation of high glucose-induced intramuscular adipogenesis in porcine muscle satellite cells. High glucose (25 mM) dramatically increased intracellular lipid accumulation in cells during the 10-day adipogenic differentiation period. The expressions of CCAAT/enhancer binding protein-$\alpha$ (C/EBP-$\alpha$) and fatty acid synthase (FAS) protein were gradually enhanced during the 10-day duration while mTOR phosphorylation and sterol-regulatory- element-binding protein (SREBP)-1c protein were induced on day 4. Moreover, inhibition of mTOR activity by rapamycin resulted in a reduction of SREBP-1c protein expression and adipogenesis in cells. Collectively, our findings suggest that the adipogenic differentiation of porcine muscle satellite cells and a succeeding extensive adipogenesis, which is triggered by high glucose, is initiated by the mTOR signal pathway through the activation of SREBP-1c protein. This process is previously uncharacterized and suggests a cellular mechanism may be involved in ectopic lipid deposition in skeletal muscle during type 2 diabetes.

Bacterial Logic Devices Reveal Unexpected Behavior of Frameshift Suppressor tRNAs

  • Sawyer, Eric M.;Barta, Cody;Clemente, Romina;Conn, Michel;Davis, Clif;Doyle, Catherine;Gearing, Mary;Ho-Shing, Olivia;Mooney, Alyndria;Morton, Jerrad;Punjabi, Shamita;Schnoor, Ashley;Sun, Siya;Suresh, Shashank;Szczepanik, Bryce;Taylor, D. Leland;Temmink, Annie;Vernon, William;Campbell, A. Malcolm;Heyer, Laurie J.;Poet, Jeffrey L.;Eckdahl, Todd T.
    • Interdisciplinary Bio Central
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    • v.4 no.3
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    • pp.10.1-10.12
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    • 2012
  • Introduction: We investigated frameshift suppressor tRNAs previously reported to use five-base anticodon-codon interactions in order to provide a collection of frameshift suppressor tRNAs to the synthetic biology community and to develop modular frameshift suppressor logic devices for use in synthetic biology applications. Results and Discussion: We adapted eleven previously described frameshift suppressor tRNAs to the BioBrick cloning format, and built three genetic logic circuits to detect frameshift suppression. The three circuits employed three different mechanisms: direct frameshift suppression of reporter gene mutations, frameshift suppression leading to positive feedback via quorum sensing, and enzymatic amplification of frameshift suppression signals. In the course of testing frameshift suppressor logic, we uncovered unexpected behavior in the frameshift suppressor tRNAs. The results led us to posit a four-base binding hypothesis for the frameshift suppressor tRNA interactions with mRNA as an alternative to the published five-base binding model. Conclusion and Prospects: The published five-base anticodon/codon rule explained only 17 of the 58 frameshift suppression experiments we conducted. Our deduced four-base binding rule successfully explained 56 out of our 58 frameshift suppression results. In the process of applying biological knowledge about frameshift suppressor tRNAs to the engineering application of frameshift suppressor logic, we discovered new biological knowledge. This knowledge leads to a redesign of the original engineering application and encourages new ones. Our study reinforces the concept that synthetic biology is often a winding path from science to engineering and back again; scientific investigations spark engineering applications, the implementation of which suggests new scientific investigations.

DAZL binds to the transcripts of several Tssk genes in germ cells

  • Zeng, Mei;Deng, Wenqian;Wang, Xinying;Qiu, Weimin;Liu, Yanyan;Sun, Huaqin;Tao, Dachang;Zhang, Sizhong;Ma, Yongxin
    • BMB Reports
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    • v.41 no.4
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    • pp.300-304
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    • 2008
  • The Dazl gene encodes a germ-cell-specific RNA-binding protein which is essential for spermatogenesis. It has been proposed that this protein (DAZL) binds to RNA in the cytoplasm of germ cells and controls spermatogenesis. Using the specific nucleic acids associated with proteins (SNAAP) technique, we identified 17 target mRNAs bound by mDAZL. Among these transcripts, we focused on TSSK2, which encodes a testis-specific serine/threonine kinase. To date, five TSSK family members have been cloned, and all are exclusively expressed in the testis. We demonstrated that in addition to the TSSK1 3'UTR, the 3'UTRs of TSSKs 2 and 4 were bound by human and mouse DAZL, and that human DAZL (hDAZL) bound to the 3'UTR of human TSSK5 (hTSSK5). Our results suggest that the Dazl gene may play different roles in human and mouse spermatogenesis by regulating different members of the downstream gene family.

Zebrafish Dnd protein binds to 3'UTR of geminin mRNA and regulates its expression

  • Chen, Shu;Zeng, Mei;Sun, Huaqin;Deng, Wenqian;Lu, Yilu;Tao, Dachang;Liu, Yunqiang;Zhang, Sizhong;Ma, Yongxin
    • BMB Reports
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    • v.43 no.6
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    • pp.438-444
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    • 2010
  • Dnd (dead end) gene encodes an RNA binding protein and is specifically expressed in primordial germ cells (PGCs) as a vertebrate-specific component of the germ plasma throughout embryogenesis. By utilizing a technique of specific nucleic acids associated with proteins (SNAAP), 13 potential target mRNAs of zebrafish Dnd (ZDnd) protein were identified from 8-cell embryo, and 8 target mRNAs have been confirmed using an RT-PCR analysis. Of the target mRNAs, the present study is focused on the regulation of geminin, which is an inhibitor of DNA replication. Using electrophoretic mobility shift assay (EMSA), we demonstrated that ZDND protein bound the 67-nucleotide region from 864 to 931 in the 3'UTR of geminin mRNA, a sequence containing 60.29% of uridine. Results from a dual-luciferase assay in HEK293 cells showed that ZDND increases the translation of geminin. Taken together, the identification of target mRNA for ZDnd will be helpful to further explore the biological function of Dnd in zebrafish germ-line development as well as in cancer cells.

Effect of Hepatic Cirrhosis on the Pharmacokinetics of Theophylline in Rats

  • Nam, Bang-Hyun;Sohn, Dong-Hwan;Ko, Geonil;Kim, Jae-Baek
    • Archives of Pharmacal Research
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    • v.20 no.4
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    • pp.318-323
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    • 1997
  • The experimental hepatic cirrhosis was induced either by bile duct ligation (BDL) or by pretreatment with dimethyinitrosamine (DMNA). The pharmacokinetics of theophylline were studied after a single intravenous or a single oral administration. Using the ultrafiltration method, protein-drug binding experiments were also carried out. The bilirubin level was several-fold increased by BDL, but not by DMNA treatment. The albumin content was decreased in both cirrhotic groups. The total clearance (Clt, ml/kg/hr) of theophylline in both hepatic cirrhosis groups significantly decreased and the terminal half-life $(t_{1/2})$ in the cirrhotic rats was increased about two-fold after intravenous and oral administration. The volume of distribution at steady state (Vdss, ml/kg) was increased slightly in the cirrhotic groups. Protein binding in BDL $(8.67{\pm}4.85%)$ decreased about four-folds, but in DMNA $(73.00{\pm}9.85%)$ similar result war observed as compared with the control. Increased free fraction of theophylline did not increase the volume of distribution in BDL. Therefore decreased total body clearance of theophylline was mainly due to decreased intrinsic clearance of theophylline in the liver. The absolute bioavailability of theophylline in these experiments was between 63.8 and 72.8%(66.1% in BDL, 63.8% in Sham operated and Control, 72.8% in DMNA). These results suggest that in the experimental hepatic cirrhosis model, administration route does not affect the disposition of theophylline.

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Administration Route Dependency of Distribution of Distribution pf PEGylated Recombinant Human Tumor Necrosis Factor Binding Protein (rhTNFbp-PEG20K dimer) following i.v. and s.c. Injection

  • Kim, Dong-Chool;Duane C. Bloedow
    • Archives of Pharmacal Research
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    • v.17 no.5
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    • pp.381-382
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    • 1994
  • Administration route dependency on the distribution of PEGylated recombinant human turor necrosis factor binding protein (rhTNFbp-PEG20K dimer) was observed following a subcutaneous (sc) and an intravenous (iv) administrationin rats. ehTNFbp-PEG20K dimer is composed of two rhTNGbp molecules (molecular weight 18, 278 daltons each) joined by polyethylene glycol 2000(PEG30K). The steady state distribution volume of rhTNFbp-PEG20K was 55 m/kg and 359 ml/kg following the i.v. and s.c. administrations, respectively. These results suggest that the distribution of ehTNFbp-PEG20K is limited within the cpillary space after i.v. administration, while rhTNFbp-PEG20K can distribute into a space (35.9% of body weight) which is between extracellylar space and total body water. A lymphatic absorption may paly a role in the distribution of rhTNFbp-PEF20K dimer following the sc administration. The present study suggests that the administration route of a lartge protein molecule should be determined depedning upon target sites.

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Spectrophotometric Determination of Antihistamines by Using Metal Indicators NN, EBT and Calcon as Color Developing Agents. (항 히스타민제의 흡광광도정량법)

  • 옥지원
    • YAKHAK HOEJI
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    • v.18 no.2
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    • pp.133-144
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    • 1974
  • The metal indicator, acidic azo dyes NN, EBT and Calcon are utilized to analyse quantitatively chlorpheniramine, tripelenamine and diphenhydramine forming insoluble ion pair in aqueous solution at proper pH values between the acidic azo dyes and the sample molecules, these compexes are extracted by organic polar solvents, and organic layer is determined spectrophotometrically. Generally, the absorption maxima of the complexes are shifted to longer wavelengths compare to the absorption maxima of the dyes themselves. The binding ratio of the ion pair forming complex molecules in chloroform soln, are as follows ; NN-antihistamines (chlorpheniramine, tripelennamine, diphenhydramine) are NN-1 to antihisamine-1, EBT-antihistamines are EBT-2 to antithistamines a and Calcon-antihistamines are Calcon-3 to antithistamines-1. These coomplexes in chloroform soln. are very stable, and show higher absorbance than the other organic polar solvents. The binding state of complexes were presumed intermolecular hydrogen bond by their infrared spectra. In the mixture solution of three samples, the aqueous phase is buffered at pH 1.0, and benzene is used to extract ion pair of diphenhydramine EBT complex selectively. At pH 1.0 of aqueous layer, Calon-diphenhydramine complex is also extracted selectively by benzene. However, in this case very small amount of chlorpheniramine-calcon calcon simultaneously. The binding state of diphenhydramine-EBT and diphenhydramine-calcon in benzene are smae as the complexes in chloroform. But the absorption maxima of the complexes in benzene are shifted to shorter wavelenlgths than the complexes in chloroform.

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Gene Microarray Analysis for Porcine Adipose Tissue: Comparison of Gene Expression between Chinese Xiang Pig and Large White

  • Guo, W.;Wang, S.H.;Cao, H.J.;Xu, K.;Zhang, J.;Du, Z.L.;Lu, W.;Feng, J.D.;Li, N.;Wu, C.H.;Zhang, L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.1
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    • pp.11-18
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    • 2008
  • We created a cDNA microarray representing approximately 3,500 pig genes for functional genomic studies. The array elements were selected from 6,494 cDNA clones identified in a large-scale expressed sequence tag (EST) project. These cDNA clones came from normalized and subtracted porcine adipose tissue cDNA libraries. Sequence similarity searches of the 3,426 ESTs represented on the array using BLASTN identified 2,790 (81.4%) as putative human orthologs, with the remainder consisting of "novel" genes or highly divergent orthologs. We used the gene microarray to profile transcripts expressed by adipose tissue of fatty Chinese Xiang pig (XP) and muscley Large White (LW). Microarray analysis of RNA extracted from adipose tissue of fatty XP and muscley LW identified 81 genes that were differently expressed two fold or more. Transcriptional differences of four of these genes, adipocyte fatty acid binding protein (aP2), stearyl-CoA desaturase (SCD), sterol regulatory element binding transcription factor 1 (SREBF1) and lipoprotein lipase (LPL) were confirmed using SYBR Green quantitative RT-PCR technology. Our results showed that high expression of SCD and SREBF1 may be one of the reasons that larger fat deposits are observed in the XP. In addition, our findings also illustrate the potential power of microarrays for understanding the molecular mechanisms of porcine development, disease resistance, nutrition, fertility and production traits.